Which under air vent is correct?

[J_Speegle]

Looks like it has some numbers on the soup lid.

Date code of when that panel was stamped

[deathsled]

Okay.  It is tough to read.  Could it be from a 68?

[J_Speegle]

Okay.  It is tough to read.  Could it be from a 68?

Stamping would be easier to rear from the other side of the panel

Yes it could be from any year but the design and style would limit that. Date stamps in sheet metal in the 60's did not include the year in the code typically

[deathsled]

Okay.  It is tough to read.  Could it be from a 68?

Stamping would be easier to rear from the other side of the panel

Yes it could be from any year but the design and style would limit that. Date stamps in sheet metal in the 60's did not include the year in the code typically

It was sold to me as a 66 on ebay.  As long as it fits I am good with it.
https://www.ebay.com/itm/185882994520